Charge forming device



1934- w. H. TEETER CHARGE FORMING DEVICE Filed Feb. 28. 1930 Zl/ilford ff Teeter Patented Aug. 14, i934 UNITED STATES CHARGE FORIVIING DEVICE Wilford H. Teeter, Dayton, Ohio, assignor, by

mesne assignments, to General Motors Corporation, Detroit, Mich.,

ware

a corporation of Dela- Application February 28, 1930, Serial No. 432,098

9 Claims.

This invention relates to charge forming devices for internal combustion engines, and more particularly to devices of this character which comprise a plurality of primary carburetors, each ,5 of which delivers a primary mixture of air and fuel to one of a plurality of secondary mixing chambers located adjacent the engine intake ports and in which the primary mixture is mixed with additional air under certain operating con- 1-0 ditions.

Devices of this general character are shown in the copending applications of Wilford H. Teeter, Serial No. 288,685, filed June 27, 1928, and Fred E. Aseltine, Wilford H. Teeter, Cark H. Kindl and Frederick D. Funston, Serial No.

370,179, filed June 12, 1929.

In devices of thecharacter disclosed in the above mentioned applications, it has been found that under certain operating conditions, there 29 is a tendency for fuel to collect on the walls of the intake passages between the point where the primary mixture is delivered thereto and the engine intake valves, particularly when such devices are used with L-head engines and the 5 primary mixture is delivered at a point below the intake valves.

It is the object of this invention to prevent accumulation of fuel on the wallsof the intake passages, as above described, and according to 3 this invention, this object is accomplished by the provision of a sump or collecting chamber located in each intake passage at a point relatively close to the valve, in combination with means to convey the fuel collected in such collecting chambers to the primary mixture passages and to reintroduce such fuel into the primary mixture flowing through the primary mixture conduits at a point relatively close to the discharge ends of such primary mixture conduits.

While this invention is more particularly adapted to an L-head type of engine than to any other type, it will be obvious that its use is not limited to this particular type of engine but will to a lesser degree, improve the opera- 5 tion of an engine of the over-head valve type description, reference being had to the accompanying drawing wherein a preferred embodiment of one form of the present invention is clearly shown.

In the drawing:

Fig. 1 is a plan view of an engine block with a charge forming device of the character disclosed in the above mentioned application secured thereto with the engine head removed.

Fig. 2 is a section on the line 22 of Fig. 1 showing the engine head as well as the block in section.

In the drawing, the engine is indicated in its entirety by the reference character 10, the block being indicated at 12 and the engine head at 14, the head being secured to the block in the usual manner by means of bolts 16. The drawing discloses a six-cylinder engine having cylinders 18 in which operate pistons 20 in the usual manner, while the combustion chambers formed in the cylinder head are indicated at 22 and the 7 water jackets in the head and the engine block at 24 and 26 respectively. Each engine intake port 28 supplies fuel mixture to two adjacent cylinders 22, a passage 29 leading from the port to two adjacent intake valves 30, as shown clearly in Fig. 1. The intake valves are operated in the usual manner and since the operating means forms no part of the present invention, it is not disclosed herein.

Associated with the engine block and supplying fuel mixture thereto, is a charge forming device which comprises a main air manifold 32, having three outlet branches 34, 36 and 38, each of which registers with one of the intake ports 28 as described in the above mentioned'applicag tio-ns. It will be noted that in the embodiment of the invention disclosed herein, the engine is of the L-head type and the intake valves 30 are located above the intake ports. The outlet branches of the manifold are provided with a taohing flanges i0 for securing the manifold to the engine block in the usual manner and when the device is assembled, such outlet branches communicate directly with the engine intake ports 28 to supply a combustible mixture of fuel and air thereto. Another flange 42 is provided at the manifold inlet to which the main carburetor unit is adapted to be secured. The carburetor unit 44 is adapted to be secured to the flange 42 by means of bolts 46, as fully described in the above mentioned applications.

The details of construction of the carburetor are entirely immaterial so far as this invention is concerned and the latter may be of the type shown in either of the above mentioned applications, or any other similar construction. It is sufiicient for the purposes of this disclosure to say that in the carburetor unit means are provided for forming a primary mixture of fuel and air which is supplied to the engine intake ports through primary 1 mixture conduits in the form of sheet metal tubes 48, 50 and 52, secured in position in the outlet branches of the manifold 34, 36 and 38 respectively. The middle one of these tubes communicates directly with the primary mixture passage formed in the carburetor unit, while the tubes 48 and 52 are connected with pipe 54 and 56 respectively, which communicate with angular passages 58 and 60 respectively, these passages in turn connecting with the primary mixture passages formed in the carburetor unit. mitted to the carburetor unit through an air valve indicated at 61 in Fig. 1, and is conveyed through a secondary air passage formed in the carburetor unit to the manifold 32 and flows through the outlet branches 34, 36 and 38 to the engine intake ports 28, in the manner fully described in the above mentioned applications.

The primary mixture flowing through the tubes 3 48, 50 and 52 is a relatively rich mixture and when this mixture is discharged from the said tubes, it has been observed that under certain operating conditions there is a tendency for liquid fuel to precipitate out of such mixture and to accumute n he wa ls. of t e as a e 29 ea from the port 28 to the valves 30 and also in the outlet branches of the manifold. This fuel will collect on the walls until relatively large drops are formed, which, when the suction is sufficient, will be drawn into the engine cylinders. This results in unequal distribution of fuel to the various cylinders with resulting ineffectiveness and irregularity of engine operation. It is the purpose of the present invention to prevent such an accumulation of fuel and to this end a sump or collecting chamber 62 is provided in each passage 29. Fuel deposited on the walls of the passages 29 will drain into the collecting chambers because of the action of gravity and tubes 6e are provided which are connected in any desirable way to the primary mixture conduits 48, 50 and 52 and ex tend downwardly therefrom into the collecting chambers 62. It will be noted that the primary mixture conduits extend an appreciabledistance into the passages 29 and the tubes 64 are located adjacent the outlet ends of such primary mixture conduits. The suction within the primary mixture conduits is greater than in the passages 29 and the fuel which runs downwardly into each collecting chamber or sump is, therefore, drawn upwardly by the suction within the primary mixture conduits and is reintroduced into such conduits in atomized form and is then carried into the cylinders. I

While in the preferred embodiment of the invention disclosed herein, the sumps are disclosed as formed within the engine block, it is not necessary that the sumps be placed in any particular position, in fact, their position would probably be different in different designs of engines and would depend in part on the shape of the passage and the point at which the end of each primary mixture conduit was located. It is merely essential that each sump be placed at a point where the fuel will readily drain thereinto and that the tube 64 extending from the sump to its associated primary mixture conduit connect with said conduit at a point where the suction is relatively high.

In the present embodiment of the invention no means, are disclosed for accelerating the flow of air through the manifold outlet branches adjacent the outlet ends of the primary mixture conduits. However, such means may be employed, if desired, and such devices are illustrate Air is ad" ed in the various applications referred to on page 1 of the patent. It has been found unnecessary, however, owing to the fact that the suction in the primary mixture conduits is greater than in the outlet branches of the manifold surrounding said conduits to employ any form of accelerating device in this relation and, therefore, for the sake of simplifying the disclosure, the accelerating device is omitted in the disclosure of the present invention.

While the form of embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to. be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. A charge forming device for internal combustion engines comprising, a mixture passage adapted to supply a combustible mixture to the engine cylinder, means admitting air to the mixture passage, a fuel supply conduit delivering fuel to the mixture passage relatively close to the engine intake valve for admixture with air in the mixture passage adjacent the point of fuel delivery, means for preventing the accumulation of fuel on the' walls of the mixture passage comprising a fuel collecting sump located relatively close to the discharge end of the fuel supply conduit, and means for conveying the fuel from said sump into the fuel supply conduit adjacent its discharge end.

2. A charge forming device for internal combustion engines comprising a secondary mixing chamber in which a primary mixture of air and fuel is mixed with additional air, a primary mixture passage delivering the, primary mixture of fuel and air to said mixing chamber, means for supplying fuel and air to said mixture passage, and means for preventing accumulation of fuel on the Walls of said secondary mixing chamber comprisingmeans for reatomizing such fuel and reintroducing same into the primary mixture passage.

3. A charge forming device for internal combustion engines comprising a secondary mixing chamber in which a primary mixture of air and fuel is mixed with additional air, a primary mixture passage delivering the primary mixture of fuel and air to said mixing chamber, meansfor supplying fuel and air to said mixture passage, and means for preventing accumulation of fuel on the walls of said secondary mixing chamber comprising a fuel collecting sump in the wall of the secondary mixing chamber, and means for reintroducing the fuel collected in said sump into the primary mixture passage. 4. A charge forming device for internal com- .bustion engines comprising a secondary mixing chamber in which a primary mixture of air and fuel is mixed with additional air, a primary mixture passage delivering the primary mixture of fuel and air to said mixing chamber, means for supplying fuel and air to said mixture'passage, and means for preventing accumulation of fuel on the walls of said secondary mixing chamber comprising a -fuel collectingisump in the wall of the secondary mixing chamber and a conduit ex tending from said sump to the primary mixture passage adjacent its discharge end.

5. A charge forming device for internal combustion engines comprising, a mixture outlet conduitadapted to communicate with the engine intake port, said outlet conduit and thepassage leading from the intake port to the intake valve comprising a secondary mixing chamber in which a primary mixture of air and fuel is mixed with additional air, the primary mixture passage delivering the primary mixture of fuel and air to the secondary mixing chamber and terminating at a point posterior to the intake port, a fuel collecting sump in the secondary mixing chamber posterior to the intake port and means for reintroducing the fuel collected in said sump into the primary mixture passage.

6. A charge forming device for multi-cylinder internal combustion engines comprising an air manifold having an inlet and a plurality of outlet branches adapted to communicate with the intake ports of a multi-cylinder engine, primary mixture conduits adapted to deliver a primary mixture of fuel and air adjacent the ends of said outlet branches, and means for preventing the accumulation of fuel on the walls of the manifold or the passages leading from said ports to the intake valves, comprising means for reatomizing such fuel and reintroducing it into the primary mixture passages.

7. A charge forming device for internal combustion engines comprising a mixture conduit formed of two parts, one of said parts being a passage formed in the engine between the intake port and the engine intake valve and the other part being a passage adapted to communicate with the first passage at the intake port, a primary mixing chamber, a primary mixture conduit for conveying primary mixture from said chamber to the first named passage forming a part of the mixture conduit, means for preventing accumulation of liquid fuel on the walls of both parts of said conduit comprising a fuel collecting sump in the mixture conduit between the intake port and the intake valve, and means to convey the fuel collected in said sump to the said primary mixture conduit.

8. A charge forming device for internal combustion engines comprising a mixture conduit formed of two parts, one of said parts being a passage formed in the engine between the intake port and the engine intake valve and the other part being a passage adapted to communicate with the first passage at the intake port, a primary mixing chamber, a primary mixture conduit for conveying primary mixture from said chamber to the first named passage forming a. part of the mixture conduit, means for preventing accumulation of liquid fuel on the walls of both parts of said conduit comprising a fuel col-' lecting sump in the mixture conduit between the intake port and the intake valve, and means to convey the fuel collected in said sump to said primary mixture conduit closely adjacent the discharge end thereof.

9. A charge forming device for multi-cylinder engines having a plurality of intake ports and passages leading from said ports to the engine combustion chambers, an air manifold having outlet branches connecting with said intake ports, fuel supply conduits delivering fuel substantially at the point of connection of said ports and air manifold, means for preventing the accumulation of fuel on the walls of the air manifold or said passages, comprising a plurality of fuel collecting sumps, each one located relatively close to the discharge end of one of said fuel supply conduits and means for conveying the collected fuel from said sumps into the fuel supply conduits adjacent their discharge ends.

WILFORD H. TEETER. 

